did you try to loosen up screws couple of turns and then tap the top of the screwdriver with a hammer (gently)? I used to do this often when windsurfing. Usually worked, but you have to be careful so the screwdriver does not slip from the screw. Or put a long screw in and tap that. Fins typically have M6 thread, but there are some with 1/4-20UNC

An advantage with Powerbox fin bases is that they were designed with the idea of the fin hitting something and coming out of the box, so on my windsurf boards I tap the powerbox fins near the top of the leading edge. If necessary use a mallet.

We usually use "foil tape" like this one. Go to home depot or similar store and look at some of them, should be in A/C/heating area. Tapes are strip of aluminum foil with adhesive on one side. Some have thick adhesive layer, do not get those, find one that is very thin.

borist wrote:We usually use "foil tape" like this one. Go to home depot or similar store and look at some of them, should be in A/C/heating area. Tapes are strip of aluminum foil with adhesive on one side. Some have thick adhesive layer, do not get those, find one that is very thin.

Cool thanks. Once I got the fins screwed in all the way, it didn't seem loose at all. Maybe no tape needed, will have to try it out and see I guess. Just need some wind now!

I also did some searching on the forum and found an old post about the original Sectors where Peter Frank says to try Gaffa tape, which is like duct tape, but the adhesive comes off cleanly.

What's the best way to hammer out the old barrel nut and put the new one in? How do you keep the new one straight when putting it in?

Is it ok to hang the fin over the edg of a table and tap the nut out of the fin? Seems bad for the fin.

Is there somewhere I can buy about 100 of these in a box for like $10? Because I think I might have messed up another one now from sand getting jammed in between the nut and bolt.

Each of my old Cabrinha fins has one of these nuts also (although they are standard, not metric). They look like they are glued in on the Cabrinha fins, anyone know if that is the case? I don't want to start hammering on them if they are glued in.

ou want to support the fin box as close as possible around the insert, so forget the table edge/fin idea. A slightly bigger washer ona firm table or bench and a good driving punch will remove the insert (glued or not). They are usually only press fitted and not glued.Nico